Audi A4, A5, Q5 backlight problem

[amigokola]

Hi Guys..
Came across two similiar clusters with common issue with backlight.
Changed all LED and testing was ok but one day later customer called that one part of tachometer was not backlighted.
There is something else that I missed.
Rgs.

[jetronic30]

Hi Guys..
Came across two similiar clusters with common issue with backlight.
Changed all LED and testing was ok but one day later customer called that one part of tachometer was not backlighted.
There is something else that I missed.
Rgs.

I encountered this problem many times in A4B8 and A6C6, but I did not find any solution

[Meat-Head]

Sounds like hairline crack in board.

get your voltage meter get it on diode test, watch it light up dim led
then follow tracks back

had a tv remote once had hairline carack could not see it, linked across and fixed

[amigokola]

First thing when I got it I checked LED's with 12V directly. Some of them didnt light up so changed all.
Twisted pcb board and all was ok. Didnt resolder resistors though so it could be it...??

Sounds like hairline crack in board.

get your voltage meter get it on diode test, watch it light up dim led
then follow tracks back

had a tv remote once had hairline carack could not see it, linked across and fixed

[Meat-Head]

Ah, led is a 2v bulb! Dont take to kindly to 12v. Feed via 1k resistance next time